Toyota Headlight System Malfunction (Solved & Explained)

The Toyota headlight system can malfunction from time to time. When the system malfunctions, don’t mess with the battery or the computer system. First, clean up the sensors, and then take them to a Toyota mechanic.

Why do Toyota headlights malfunction and how can the issues be fixed?

In a car, truck, SUV, etc, the headlight system has several components, including the wiring, the lightbulbs, the lightbulb mounts, the switch that turns the lights on and off, and the wires that connect to the battery, and the headlight sensors.

When the headlight system malfunctions, a message will appear on the dashboard. The message will say, “Headlight System Malfunction. Visit Your Dealer.”

So, what could cause a Toyota headlight system to malfunction?

A headlight is burning out – the headlight system will warn you if a headlight is about to burn out. On average, a headlight should last at least 1000 hours. Some headlights last much longer than that but 1000 hours of illumination time is standard. After a headlight burns out, you will need to replace it. Most headlights are sold in pairs, so when you purchase a pair of headlights you might as well replace both of them.

The headlight auto-leveling system is not working – auto-leveling headlights are headlights that ‌adapt to the position of the vehicle and keep the lights coming from the headlights constantly on the road. These self-adjusting headlights change position on their own. In some cases, headlights are no longer in the right position and the sensors cannot detect what position the headlights should be in.

In order to fix a headlight auto leveling malfunction in a headlight system, you must first look for an automatic headlight leveling system warning light. If the warning light is flashing, then you can take your Toyota vehicle to a certified mechanic to have them run a Diagnostics test. 

If you still have your Toyota vehicles manufactured, you can use the manual to find the fuse that connects the computer to the headlight system. Sometimes the fuse will burn out and the computer can no longer talk to the headlight system to engage the automatic leveling program.

Water or mud found its way into the headlight – occasionally, sand, mud, or water, can find its way between the crevices of the headlight cover, and dirty the headlights are the censors. If you see that there are particles picking the inside of the headlight color, you need to take the headlight cover off and clean in and around the headlights. If the area is particularly dirty, you may have to take the headlight out and clean the socket.

Be sure to clean all the sensors too. Sensors can easily short out if they are exposed to dirt or water.

Note: if you live in an area that experiences a lot of rain or is humid all year long, then get into the habit of checking underneath your headlights regularly. Even a few drops of water can ruin a headlight and short out the bulb or the fuse.

The high beams turn on automatically – it is actually a feature of the Toyota headlight system. If you notice that the headlights turn on when you turn on the engine, then you must have the automatic high beam settings turned on. 

If you do not want the high beams to turn on automatically, then you can turn the setting off yourself.

First, leave the vehicle on and check to see that the vehicle is in park. Then, locate the headlight lever. Grab the headlight lever and pull it towards the driver’s seat and hold it down for 40 seconds. After 40 seconds, the auto high beam indicator on the dashboard will blink twice. That is how you know the automatic high beams are now turned off

If you want to turn the automatic high beams back on, pull the headlight lever towards the driver’s seat and hold it for only 30 seconds. This time, the auto high beam indicator will only blink once to show that it is back on.

Should you reset the headlight system yourself? No!

Are you still not sure what the issue is? If the headlight warning signal is still flashing under the dashboard and you do not know what the issue is, then you will have to take your vehicle to a mechanic. Fixing your vehicle DIY style can only go so far, and you can ruin other parts of your vehicle if you don’t know what you’re doing. 

But you may have looked online and saw that some people are disconnecting the headlight system from the battery. They are doing this to reset the system.

However, resetting the headlight system by disconnecting the battery is not a good idea.

First‌, it will clear none of the data that the computer has gathered. Even if there are issues with the computer, the computer will lose none of its data.

Second, messing with the battery is not a good idea if you have no experience working with it before. 

Third, you could bend or break something when you disconnect the headlight system from the battery. Breaking a part of the battery or connection to the battery will cause your repair bill to skyrocket.

Clean all the headlight sensors

Sensors are easily affected by everything in their environment. So, when you see the headlights system malfunction warning on your dashboard, ‌ clean the sensors first and then try every other solution we listed above. There are special sensor cleaning solutions that will not damage the surface of the sensor or the wiring. If you don’t have the solution, use a window cleaner.

Conclusion

There are several reasons why the Toyota headlight system malfunction light will appear on the dashboard or console. Water or mud could be affecting the headlight or its wiring. The high beams are automatically on when they should not be. A headlight is burning out and needs to be changed. Or the auto-leveling system is no longer functioning as it should. 

All these issues are quite fixable; you may be able to fix them by yourself. But do not reset the headlight system by unplugging the system from the battery.